#include<iostream>
#include<iomanip>
using namespace std;
const double PI = 3.141592;
int main(){
    cout<<PI<<endl
        <<setprecision(0)<<PI<<endl
        <<setprecision(1)<<PI<<endl
        <<setprecision(2)<<PI<<endl
        <<setprecision(3)<<PI<<endl
        <<setprecision(7)<<PI<<endl;

    int b = 100;
    cout<<"Dec:"<<dec<<b<<endl
        <<"Hex:"<<hex<<b<<endl
        <<"Oct:"<<oct<<b<<endl;

    cout<<b<<endl
        <<100<<endl
        <<"Input b = ";
    cin >> b;
    cout << b <<endl;
    cout << dec << setiosflags(ios_base::showpos) << b << endl;
    cout << "Input b = ";
    cin >> b;
    cout << b << endl;
    cout << resetiosflags(ios_base::showpos);
    cout << b << endl;


    return 0;
}

